The researchers, from the University of Minnesota’s department of food science and nutrition, used paired comparison tests for broth and salt-in-water solutions to determine thresholds at which trained sensory analysts would notice a reduction in sodium content. They established two series of concentrations from these thresholds; 12-step reduction for the more complex broth, and a 26-step reduction for salt in water over a 10-month period.
“The series of salt concentrations determined in this study provides a foundation for food manufacturers interested in reducing salt content of processed foods, and basic information for people interested in reducing their personal dietary salt intake without adversely impacting product acceptability,” the study’s authors wrote.
“The strategy of gradually decreasing salt content of foods is currently being considered by the Food and Drug Administration for industry-wide application, and if successful, has the potential to significantly reduce rates of health conditions related to overconsumption of salt.”
The researchers explained that the task of discriminating saltiness in a more complex broth is more difficult than in a simple salt-in-water solution, so it may be more difficult to predict what level of salt reduction is possible in a more complex food product at each stage.
“However, approaching salt reduction more conservatively by using smaller steps than defined in broth is a viable option,” they wrote.
The Institute of Medicine (IOM) outlined a strategy of gradual stepwise reductions in sodium across the food industry back in 2010, and urged the Food and Drug Administration (FDA) to take action by setting mandatory standards for industry. Since then, the FDA has continued to support voluntary industry measure to reduce sodium content in foods, but has not mandated particular targets.
“Our inherent taste for salt, however, has presented a large challenge to food manufacturers, particularly in ensuring consumer acceptability of low-sodium foods,” the study’s authors wrote.
They concluded that the steps detailed in the study may provide “a conservative foundation for gradually decreasing salt in food products to a low-sodium target.”
According to IOM figures, the average American consumes 3,400mg of sodium a day – about one and a half times the USDA’s suggested upper limit of 2,300mg – and 1,900mg more than the American Heart Association’s suggested maximum daily consumption level. The food industry has been under pressure to reformulate products with lower sodium, as processed foods are thought to contribute about 80% of the sodium in the average American diet.
Source: Journal of Sensory Studies
DOI: 10.1111/j.1745-459X.2012.00379.x Vol. 23, Iss. 3, pp. 168-175, June 2012
"Determining Sequential Difference Thresholds for Sodium Reduction"
Authors: Nuala Bobowski and Zata Vickers